FIGS. 1a to 1c show a conventional method of forming a damper assembly 10, specifically forming a flange-hub sub-assembly of damper assembly 10 formed by staking a damper flange 11 onto a damper hub 12. Damper hub 12 is formed of a forging material and damper flange 11 is formed of a case hardened stamped flange for forging damper hub 12. As damper flange 11 is pressed onto damper 12, an inner circumferential splined surface 14 of damper flange 11 spline cuts an outer circumferential surface 16, displacing material 18 (i.e., creating chips), of outer circumferential surface 16 of damper hub 12. Damper hub 12 is provided with a chip pocket 20 at outer circumferential surface 16 to receive displaced material 18. Following the storage of displaced material 18 in pocket 20, damper hub 12 is staked or coined to fix damper flange 11 axially on damper hub 12.
U.S. Pub. 2009/0266665 discloses a hub in which, radially at the inside, an end of a transmission input shaft is arranged in a rotatable fashion and on which, radially at the outside, a piston of a converter bypass clutch is mounted axially movable and rotatable; the hub may be caulked with the converter cover.
U.S. Pub. 2016/0025154 discloses another method of fixing a damper flange to a damper hub. For splines having large radial lengths and/or axial thicknesses, this method, and the method of FIGS. 1a to 1c, may result in gaps 22 being left in between the splines of flange 11 and the outer circumference of hub 12, as shown in FIG. 2, impacting the torque transmission ability of the damper assembly.
FIG. 3 shows a damper sub-assembly 24 including a damper flange 26 and a damper hub 28 integrally formed together in a one-piece design that typically requires more processing (machining and stamping) than damper assembly 10 and is typically more costly than the hub design 10.